The invention is based on a hydraulic dual-circuit brake booster for a vehicle brake system.
A brake booster of this kind is known (German Offenlegungsschrift No. 25 31 264). In this known brake booster, however, only one brake circuit is closed, while the other is open and is supplied directly by the pressure directed into the system by the control valve. If the pressure supply fails, the open brake circuit becomes a closed brake circuit. The disadvantage then, however, is that if there is a defect in the open brake circuit the pressure supply for the entire system fails.